1. Field of the Invention
This invention relates to an improved chime with high strength hollow beam construction for increasing the compressive strength which a fibre or other drum can bear.
2. Description of the Prior Art
It is well known in the prior art that the weight of a single filled drum (which is on the order of 500 pounds for a standard fifty-five gallon drum) and its contents in a static position account for only a fraction of the load which a drum must be designed to bear. Stacking of several drums one on top of another is inevitably done in transportation or storage locations in order to optimize the use of available space. This increases the static loads on the drum or barrel. However, additional strength must be built into the drum or barrel to assure that rough handling, such as might occur if a drum placed on top of other drums is lowered too quickly by a forklift truck thereby producing an impact which tends to crush the lower drums, does not compromise the integrity of the drum or barrel.
It is well known in the prior art to use a metal chime on the top and bottom of fibre or other drums or barrels to make sturdy closures which hold the bottom securely to the end of the drum shell and to provide a sturdy place to fasten the lid in order to prevent the contents from leaking or bursting from the drum. As the vertical sidewalls of the drum near the intersection of the sidewall and horizontal top or bottom of the drum are most susceptible to deformation and failure (particularly if dynamic forces are applied unevenly, such as if the drum is dropped or impacted on one of its corners), reinforcing chimes must be designed to add extra strength to the barrel or drum in anticipation of excessive external forces as shown in U.S. Pat. Nos. 4,720,038; 4,457,465; 4,483,456; 4,378,328; and 3,116,001.
Many drums are currently made from fibreboard due to its low cost and ability to bear high compressive forces. In order to take advantage of these properties in a wide range of applications, the fibre drums must be reinforced with more force resistant chimes.
However, while the use of heavier fibreboard and thicker metal chimes results in stronger barrels or drums, economic considerations require that the drums be made of conventional thickness fibre board and as thin of metal chime material as possible, in order to reduce manufacturing costs, to avoid a diversity of drum manufacturing inventory and equipment, and to avoid departing from the standard outer dimensions of a drum of a given capacity.